Six months of waiting. A year of training. Perhaps a lifetime of dreaming. The race is finally underway, yet you feel rundown and lacklustre. There is a scientific term for it, but let’s just call it a bad race day. Everyone has experienced it, from Paula Radcliffe to yours faithfully (occasional amateur).

The next generation of running technology, and in particular more accessible blood testing, promises to help avoid such frustrating and unexplained dips in performance. We can monitor our heart rates and sleep, but within five years we could have instant access to a whole range of data linked to physical performance, including red blood cell count and vitamin D and iron levels.

“Strava is brilliant because you can track your performances over time, but if we looked at your profile we could see potential issues straight away,” says Dr Brian Moore, who runs the company Orreco that uses the technology on elite runners. “Your muscle damage might be high, your immune system might be compromised, your haemoglobin might be low, which means there might be a problem in the weeks or months to come.”

It’s already known that many women could be turning up to races with low levels of iron. Going by a study of runners at the London marathon last year, heavy menstrual bleeding is affecting more than a third of female athletes and is linked to both iron deficiency and negative performance. Lower iron levels reduce the body’s haemoglobin levels and our ability to deliver oxygen to muscles, leading to fatigue.

“There are women out there effectively suffering in silence,” says Georgie Bruinvels, 27, a PhD student and Great Britain runner researching the topic at St Mary’s University, London. “They are massively at risk, but until you are woken up to it you probably don’t realise you could be affected by it.” Moore says a blood test every couple of months would help athletes adapt their training, sleep and nutrition before it affects performance.

There are companies in the US offering tests – starting at £200 each – to amateur triathletes and endurance runners, with samples sent off to laboratories. Moore reckons the rapid progress in fingerprick blood-testing means there could be handheld products on the market within five years.

There are also concerns about doping. In the US, blood tests for low testosterone have become common, especially for men over 40, and have led to the wider use of illegal replacement therapies. “As amateur athletes are rarely drug tested, this can increase the temptation to cheat,” says Dr Andrew Kirkland, a coach and sports scientist at Stirling University. “There are certainly anecdotal reports of an increased use of human growth hormone and blood boosters in amateur sport, in which blood testing may be a gateway to such abuse.”

But Moore says the work his company is doing with elite athletes is proving that blood and other biomarker data is a way to improve performance, rather than resorting to cheating. “Our passion is helping athletes to achieve peak performance, using 100% of their natural talents. Any athlete, professional or amateur, that cheats is really just cheating themselves.”